[GBC] Akiyuki Train System: Type 2 mods and improvements

[doug72]

1 minute ago, Berthil said:

@Doug72, I have the same experience with the elevator and have done about the same settings and tryouts until I found a good equilibrium between all switches and rubber bands.
Looking at how everything has to work together, it's surprising it kept working for 4 hours yesterday.

Based on your cycle times and balls per trip estimate you moved over 19636 balls yesterday - thats a lot of balls !!!

[doug72]

Elevator Trouble:

Further investgation has found a weak rubber band - see image.
Left: blue band in use on elevator trip for lowering had streched !
Not sure if was a 25 or 26 band or if brand new when received.
Right: new blue 25mm blue band

Now tested elevator with a red 25 mm band without the double wrap on one ball pin and working OK.

Something to watch over time & check if any issues as there is tension on this band even when not in use.
Wonder if high ambient temperature could be the cause.

PS the band seems to be slowly returning to normal size now there is no tension - odd.

Edited August 27, 2018 by Doug72

[Berthil]

I am working in the synthetic rubber branche for over 30 years at the largest synthetic rubber producer in the world.

I'm glad the LEGO coloured bands are not natural rubber anymore as they loose elastomeric properties under the influence of UV light (polymeric chains break). The black ones diminish over time as no doubt every AFOL has noticed.
Natural rubber however is the best elastomer for dynamic properties, property number one for elastic bands.

I think current bands are Butyl (IIR, Isobuytlene-Isoprene copolymer) rubber, the next close thing to natural rubber when it comes to dynamic properties.
Or it is EPDM which is better UV resistant and better colorable but has less dynamic properties. EPDM is an Ethylene Propylene copolymer (with a third monomer) most commonly used in your black door profiles of your car.

What you see in the bands is called creep which below picture shows on stretch (blue line) and release (red line), especially the release. Lots of factors influence the lines but it is certainly also temperature dependant where cold is actually worsening dynamic properties instead of warmth. So we shouldn't store the Rotary Dumper at very low temperatures :)
On very good dynamic properties red line comes closer to blue, on worse further away from blue and also not coming back to starting point (which means longer bands after stretch), especially after a long stretch (elongation). So never overstretch the LEGO rubber bands :)

 

Edited August 27, 2018 by Berthil
typos

[doug72]

@Berthil

18 minutes ago, Berthil said:

I am working in the synthetic rubber branche for over 30 years at the largest synthetic rubber producer in the world.

Thanks for that information, perhaps if we don't run our train systems for long time, it would be best to release the tension of all rubber bands used including the reversers.
As they are relatively cheap compared to shock absorbers I shall keep a few spares.

Edited August 27, 2018 by Doug72

[RohanBeckett]

I thought the modern lego bands (anything non-black) were silicon based?

I've definitely got a few, that came in the old AirClaw rig, and Shuttle, from the early 90's and they are still good to this day - 20+ years later

 

[Berthil]

1 hour ago, RohanBeckett said:

I thought the modern lego bands (anything non-black) were silicon based?

I've definitely got a few, that came in the old AirClaw rig, and Shuttle, from the early 90's and they are still good to this day - 20+ years later

Could also well be silicone rubber, one of the most expensive synthetic elastomers and very resistant against UV and lower temperatures, typically door seals in airplanes are made of silicone rubber.
Probably yours do not contain natural rubber and if so, keep them away from light :)

I don't think we have to worry about storing the Rotary dumper with bands in place as long as they are not stretched too much. I only have red bands in place which are almost at their relaxed position.

[doug72]

Yattaran Rotary Dumper ( Reverse engineered )

So far have built the longer rotary frame, hopper wagon, track and the reverser track on the test rig.

Progress has been slow and very frustrating with all sorts of problems.
Mainly due to obtaining an effective way to un-couple the train from the hopper wagon.

The video shows a big jolt when this takes place. I found it takes a lot of force to pull apart the Lego train magnetic couplings which causing the dumper frame to distort in direction of travel. 
On the rare occasion the coupling parted the hopper wagon was catapulted backwards out of the dumper as frame return to original position.

So a radical rethink required.
Concluded that the Yattaran dumper is over engineered and very complex and have therefore abandoned in further attempt to replicate it.

Instead I will design my own version (D’sRD) of a rotary dumper that will allow the  train to run through & stop in the reverser but at same time allow the dumper to rotate to empty the hopper wagon. Wether this will be partial or full rotation, have yet to decide. This is how some rotary dumpers work which requires rotary couplings.

My D’sRD version will use a Z28 turntable to achieve this and will use the short dumper at in order to use 1 x 16L track beams

Side view showing train coupled to hopper wagon.

End view showing train alignment as it as it would pass through the dumper before engaging with the train reverser.
Horizontal grey beam with green pin is only to show that the Z28 turntable rotates around the dumper horizontal & vertical centre line and allows the hopper wagon to rotate & empty while still connected to the train.
Synchronisation should also be easier.

Edited August 28, 2018 by Doug72

[Berthil]

Video of the Sunday event and test setup where all the black and grey stuff is mine :) 

The train has a little difficulty to engage the switch to go down because the Lithium battery is already a bit lower but all still works.

Like the Japanese I also have a tendency to over engineer but am getting better at simplifying for more reliable modules :)

[doug72]

Great to see it running well at a public event.

[doug72]

8 hours ago, Berthil said:

 

Original design by Akiyuki, modification by Doug72.

 

[dunes]

right Doug !

[Berthil]

I didn't make the video and told the video maker half of the Rotary dumper wasn't Akiyuki anymore.....

[doug72]

30 minutes ago, Berthil said:

I didn't make the video and told the video maker half of the Rotary dumper wasn't Akiyuki anymore.....

I thought that was the reason.

Work on new through dumper going well, thought there would be a problem getting the gear ratios correct as can only get a 12T gear to drive the large 140T gear ring, A 20T gear would foul the underside of the train, but now figured how to get same gear ration of 21:1 so train release will be in sync with full rotation, using a 56T turntable for the reverser.

Now tested and works fine with train stationary in the reverser and dumper rotated by hand with hopper wagon inside. The rotary connection between train & hopper wagon works well.

Drive to dumper still to install.

It will be a lot shorter overall than the Yattaran module.

Edited August 28, 2018 by Doug72

[RohanBeckett]

Dougiyuki!

or AkiDoug!   

:D

[doug72]

Doug's :- Rotary Dumper - Through type with sepearate hopper wagon.

Success it works

After an epic struggle to get the drive from reverser to turn the rotating dumper finally achieved it,

First test failed & tracks would not align properly, found I had forgotten a 24/8 reduction in the reverser but easily fixed.
Tested again and tracks line up and train enters & leaves OK.

Dumper rotation very smooth and timing very easy to set.

I have opted for full rotation.
Reversers uses rubber band & the Z56 turntable as a gear to achieve the 21:1 reduction required to rotate the dumper 360 degrees.

Tested with hopper wagon attached and entered and rotated in the dumper while still connected to the train as it drove everthing in sync.
The rotating coupling works smoothly.

Some images below - I will describe more fully tomorrow.
Devising gear trains for rotation was the biggest problem, the dreaded1/2 stud offset at work again !!!
Video later.

Track to be extended and the loading station built.

Once all built I will make a proper frame structure to support everything.

Next task is clean up my work station - its a mess with unused parts all over the place.

 

See next post for more images, video and a more detailed discription.

 

Edited August 30, 2018 by Doug72

[doug72]

Video of dumper rotating with the hopper wagon in dumper and the train unit driving the dumper and the reverser.
Note:- trip arm removed from the reverser for video purpose only to demonstrate the rotary coupling between hopper wagon and train unit.

 

General view:

General view:

Reduction gearing to drive dumper at 21:1 reduction
There was insufficient room to install a drive to the 140T gear ring for dumper at the reverser end.
So had to devise away the drive the other 140T gear ring
It took quite a while to sort this out as could not use a 20T double bevel gear meshing with the 140T ring to get the required 21:1 reduction as it would foul the underside of the train as it passed over.
Tried an offset drive axle but run into problems with the dreaded 1/2 stud offset, due the need to use studded technic beams etc.
Eventually came up with a drive on the centre line.
2 x 12 gears on same axle act as idler gears, the top 20T gear drives the outer 12T gear.
A second axle has a 20T engaging the other 20 T gear & on same axle there is a 24T spur gear, driven by a 8T gear from the reverser via a drive axle 44L long.
This setup gives the required 21:1 reduction in a compact unit.

Drive from reverser to long axle that drives the gearing to rotate dumper.

This required two LEGO Beam 3m Ø4.85 with fork (87408) at 90 degs to each other and 1L apart.
Connection seen in video a bit weak so have devised a stronger connection.

Reverser unit:
A more compact version devised with Z56 turntable & rubber band.
Overall trip rotation is 21:1 via 24:8 & 56:8 = 3 x 7 = 21;1 to be in sync with dumper drive.

Timing:
This is easy to adjust in 140 steps by removing the outer 12 double bevel gear- adjust 140T ring gear and slide the gear back into place.

Tested hopper & train enter and exit dumper OK.
Next step is to build the loading station and reverser plus a elevated track section or possible a different type of elevator.

Studded base plate
This is non Lego but I find it very usefull when building as you can re-aranage parts quickly instead of having to build new frame supports.
Once build is finished - base plate removed and proper framing added between the various sections.

Edited August 30, 2018 by Doug72

[dunes]

This looks awesome Doug. You're fast and efficient.

it gives me always headaches when it comes to gears and their reduction calculation.

[doug72]

13 hours ago, dunes said:

This looks awesome Doug. You're fast and efficient.

it gives me always headaches when it comes to gears and their reduction calculation.

Thanks for your comments.
There is still room for improvements for the rotating dumper / reverser unit.
The two 140T gear rings were "racking" as hopper wagon entered & exited the dumper.
 Two additional stiffening axles added at 90 degs to track and hopper guide rails and extra 2L pins added to gear segments to stop any spreading, 

Rotary Coupling:
At the moment only straight tack can be used as only rotates in a horizontal direction, for curved tracks a flexible coulping has to be able to move in both vertically and horizontally. Still looking for a solution.

Re Baseplate - 56L X 28L:
Have shifted the  / reverser dumper unit so that the end of first section of track rail is in line with the edge of the baseplate.
 The other baseplate will have the loader station and reverser with its track rail end  lining up with edge of baseplate.
The two units can then be worked on individually and linked togeteher once all OK.
Overall length will be 112 L or 89 Cm.

I have had the train and hopper wagon running back and forth repeatedly (reversed by hand at loader end) to sort out some issues and extra guide beams added to ensure wheels roll over the joint between static & rotating track rails..
There is a 0.5 mm difference in rail height between track in the dumper & the elevated track section.
Can't find a way to eliminate this but train wheels cross this OK with just a small bump.

Next step is build the reverser for the loading end. Train car has to be slightly adapted so it hits the stop but at same time allow the hopper wagon to preceed it.
Extentions added to one end of train unit to align axle 8T gear with the reverser 24T gear.

Re Gear reduction calculations:
When designing I often while watching TV have a note pad, pen & a calculator to sketch out ideas  etc.

@Sariel Lego technic Builders guide 2nd edition has a gear reduction chart on page 59. - very usefull

Yoshihito Isogawa "Machines & Mechniams" book has a good section of meshing gears to obtain different ratios by using unusual gear combinations & parts etc..

Edited September 1, 2018 by Doug72

[doug72]

Doug’e Rotary Through Dumper Module.

Hopper wagon, improvements

Have discarded the original hopper retaining system of 4 rollers high above the hopper wagon.
It was hard to get the position of the retaining beams correct to hold the hopper in place, being either too tight or too loose.

Improved system built which has two beams that can swing slightly.
As the hopper wagon enters the dumper is raises the beams slightly to allow hopper to enter, these then lock in place and prevent the hopper moving as dumper rotates and dump the balls.

Restraining beams in lowered position.

 

Restraining beams locked.

Short video of improved hopper wagon dumping balls.
Best viewed at half speed. Hand operated for testing purposes.

 

 

Edited September 2, 2018 by Doug72

[dunes]

This really a clever idea and looks realiable.

[doug72]

WOW that’s quick, LDD looks great.

As Train & Hopper reverse out of the dumper the restraining beams swing back down again due frictionless pins.

Almost finished the bespoke reverser for the loading end & made a small mod to the rubber band trigger arm.

The cross block 90º 1 x 2 gives added support for ther trigger arm.

 

 

Edited September 2, 2018 by Doug72

[doug72]

8 hours ago, dunes said:

This really a clever idea and looks realiable.

Might see if it would work with the unloader module, which has very tight clearance to grip the sides of ball hopper & raise it to dump balls.

Often the hopper fails to enter the lifting arms.

Edited September 2, 2018 by Doug72

[doug72]

Loading end reverser installed and testing commenced with GBC balls.

Two issues found:-
1/. Reverser trigger snaged on the sides of the hopper wagon due to the side ribs on the 8 x 8 Lego panels.These shifted over 1 stud and the exposed studs were covered use tiles, the 3 x 3 swing lever on trigger arm now runs along these OK.

2/. Some balls escaped as dumper rotated, shifting Lego panels prevented some balls hanging up on the lip caused by the locking beam. Others escaped at the ends of the hopper.
Two LEGO Lattice for Frame 4 x 6 (92589 added to the rotating dumper prevent this. Re-tested and all balls now fall into the container below.
The four 2 x 4 angle beams had to be reversed to order fit the lattice frames.
Collection chute still to build.

Hopper wagon can carry and dump up my entire stock of 72 balls.
More than enough to meet GBC ball rates.
————————————————————————————————-

The drive from the the reverser to rotate the dumper has to run through two 90º turns  Also due to use of studded & studless technic beams there was a slight alignment problem.

Now re-building rotary dumper on a frame instead of studded baseplates.

 

Original version - complicated and unable to accommodate alignment issue

 

Improved version which use the LEGO Minfigure Neck Bracket (42446) to correct the alignment problem.

Edited September 4, 2018 by Doug72

[doug72]

Doug’s GBC Train system:

A module in two halves:-
Now completed and tested OK with some minor issues sorted.
The two modules plug together and easier for storage / transport.
Both removed from baseplates and now supported on a higher support framing.
Transfer from baseplates not straight forward due the 1/2 L offset problem, but now resolved.

+

=

 

Hopper wagon wheels:- Update
Under carriage now re-designed to be able to use train wheels on 6L axles, rides along guide beams OK and much smoother without any bumps.

Next stage is to build a module to load the hopper wagon and then the discharge conveyor module, both to be driven by the train unit.

Video coming soon.

Edited September 7, 2018 by Doug72

[Berthil]

Looking good Doug. It will still be quite some work to integrate in the train circuit with a high enough input and output.

Since I am now using rechargeable trains I thought I add an electric power station to the loader :)
Ik wanted to use only parts that I already had as a challenge, no Bricklink orders.
It shows I also like Modular buildings and it is completely different from the technical work done here but I hope you like it.

Edited September 7, 2018 by Berthil
Typos